A crew’s needs may well change during a session depending upon their exertion and weather conditions. Therefore, the key to appropriate clothing is layering to keep warm and maintain the right body temperature even when wet. Also remember that you can get hot when rowing but will cool down quickly when you stop.
Rowers should wear a thin, tight fitting base layer to wick away moisture from the skin – a technical/synthetic fabric is best for this; then a synthetic fleece as a mid insulating layer, followed by a wind blocking but breathable and well ventilated top layer which can also be water resistant or shower proof.
Weatherproofs are not necessary for rowing but if you do purchase one it should be breathable and most really waterproof clothing tends not to breathe well and so holds perspiration within the clothing.
In cold weather it is important to wear an insulating hat e.g. a woolly hat, to avoid heat loss and in the summer (and at times in the spring/autumn) a peaked cap and sunglasses are useful additions. Gloves are useful but if not tight may cause blisters and many rowers opt for cycling gloves.
Footwear of some kind must be worn in the boat. In the summer, sandals,“crocs” or trainers usually suffice though the latter provide more protection. In colder weather trainers combined with waterproof synthetic socks will help keep the feet warm even if wet. Neoprene boots with/without socks also work reasonably well.
Wellies are useful when launching/recovering the boat but not recommended for rowing as they can easily fill up with water and they are cumbersome should you end up in the water.
It is worth investing in a simple dry bag for storing your bits and pieces e.g. gloves, woolly hat, sunglasses etc. when rowing.
Sometimes someone will need to wear waders or a wet suit to launch/recover the boat and these will be available when needed. Neither are suitable for rowing.
Finally, it is advisable to bring a change of clothing to go home in at the end of a session in case you have got wet.